You can probably already guess what's going on here ;)
I found an old calculator that also has a small printer built in! So after quite a while of not touching this project, I finally have a good reason to work on it again! This printer is a perfectly suitably extension for my IO interface! I already took the calculator apart, now I am 'hacking' it, will wire it to some glue logic so i can hook it up to the interface and finally do something useful! Like calculating and printing out primes for example! I'll shoot another video when it's done :)